Anode electrode for electron discharge devices and method of making the same



Sept. 29, 1964 J. F. STEPHENS 3,151,265

mom: ELECTRODE FOR ELECTRON DISCHARGE DEVICES AND METHOD OF MAKING THESAME Filed Feb. 5, 1962 FIG.I.

FIG.4.

FIG.8.

Ec I O VO E6 IO VOLTS INVENTORZ JOE F. STEPHENS,

5;, VUL rs United States Patent 3,151,265 ANUDE ELE CTRGDE FGR ELEQTRONDHSCHARGE DEVECES AND METHQD 9F MAKING THE SAME .loe F. Stephens,(iwenshoro, Kym, assignor to General Electric Company, a corporation otNew York Filed Feb. 5, 1962, Ser. No. 170,9e9 6 Claims. (U. 313-356)This invention relates to power tubes and in particular to the structureof an anode for a beam power tube or the like to minimize variousoscillations within the tube and to a method of forming such an anode.

Beam power tubes are electron discharge devices, which usually include acathode, an anode, a control grid, a screen grid and shaped electrodesfor the purpose of concentrating and confining the electrons in theshape of beams. In addition, the grids of said tubes may have parallelspacings to further concentrate the electrons in beams. The electrondensity affects the space charge region existing between the screen gridand the anode to produce a negative voltage gradient near the anodewhich acts as a virtual cathode and eliminates the necessity of asupressor grid in reducing secondary emission effects. Beam power tubeshave the advantages of high power output, high power sensitivity, highemciency and are consequently extensively used. This type of tube likeany other tube has a family of plate voltage versus plate currentcurves, with different control grid voltages, characterlzed by a sharprise in plate current with initial increase in plate voltage and asubsequently fairly flat portion with increasing plate voltages. At thejuncture of the two portions of the curve, a sharp bend or knee occurs.When this knee is at a high plate potential level the tube may give riseto RF. radiations. This is particularly of concern when the tube isdriven to values orplate potential that are less than that at which theknee appears. When using beam power tubes in the horizontal deflectioncircuitry of television receivers, such RF. radiations may be picked upby the antenna or parts adjacent the tube, and transmitted through theset giving rise to jagged vertical lines at the right hand side of thepicture tube, these lines being known in the art as snivets. At lowerplate potential levels of the knee, such conditions do not arise. Thesespurious oscillations or snivets emanating from the beam power tubes mayappear as cyclic interference on one side of the picture tube raster asa vertical band or hands, either curved or straight, continuous orbroken, depending upon the strength of the spurious oscillations.

in the prior art the removal of the spurious oscillations or snivets hasbeen accomplished by lovering of the knee voltage by bringing portionsof the tube anode closer to the grids, but with portions of the anodesufficiently spaced from the beam confining plates so as to preventflash-over. Protuberances have been extruded from the anode toward thegrids to extend the anode electrostatically closer to the grids as shownin Patent 2,857,544. Other prior art devices have utilized internal finsmade of strip material jig-held to one half of the anode and weldedwhile so held or by the use of additional material in the form of a fininsert assembly to fit between complementary anode halves of the anodestructure of a beam power tube such as shown in Patent 2,843,787. It isto an improvement on the latter type of construction that this inventionis directed.

Accordingly, it is a principal object of this invention to provide animproved method for forming an anode of a beam power tube with aninternal fin assembly.

A further object is to provide a method of forming an anode with anintegral internal fin assembly with greater ease of fabrication andreduced cost.

cs ea Yet another object is toprovide an improved anode structure withan integral internal final fin assembly for use in a beam power tube orthe like.

The method of obtaining the foregoing objects of forming an anode of abeam power tube with an integral internal fin assembly includes, in oneembodiment, the steps of first, forming a first channel-shaped memberhaving a pair of side walls and an end wall with the respective flangemember extending outwardly from one end of each side wall. Each flangemember forms an essentially right angle with the ends of each side wall.The second step includes bending each flange member to form respectivefirst and second sections with the second sections overlying the firstsections and extending inwardly past respective side walls to forminternal fin members for the anode when finally assembled. It is thesefin members which operate to lower the knee voltage of the beam powertube, thereby removing the spurious oscillations by bringing portions ofthe tube anode closer to the grids. The third step includes forming asecond sheet of material into a second channel-shaped member having apair of side walls and an end wall with a respective flange memberextending outwardly from one end of each side wall. Each of the flangemembers of the second channel-shaped members forms an essentially rightangle with the ends of each side wall and is adapted to overlierespective flange members of the first channel-shaped member, when thetwo channel-shaped members are joined. The fourth step in the forming ofthe anode with integral internal fin assembly includes securing saidfirst and second channel-shaped members together by any known meanswhich may include welding of the respective flange members together.

Other objects, features and many of the attendant advantages of theinvention will be appreciated more readily as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings wherein:

FIG. i is a side elevation view of a first piece of blank stock fromwhich the anode is to be formed;

FIG. 2 is a side elevation view of the first piece of lank stockfollowing a first forming step;

FIG. 3 is a side elevation view of the first piece of blank stockfollowing a second forming step in which the integral fin assembly isproduced;

FIG. 4 is a side elevation view of a second piece of blank stock;

FIG. 5 is a side elevation view of the second piece of blank stockfollowing a first forming step;

FIG. 6 is a side or end View of the tubular anode assembly aftermanufacture but prior to final assembly within the discharge device;

FIG. 7 is a sectional view of a beam power tube comprising the anodestructure of the invention; and

FIG. 8 is a graph of plate current versus plate voltage characteristiccurves showing the comparison between beam power tubes incorporating aninternal fin assembly and those without such an assembly.

Referring to the drawings and particularly FIG. 1, there is shown anelevational view of a piece of blank stock prior to being worked to formone half of the anode assembly of a discharge device such as a beampower pentode. FIG. 2 shows the first piece of blank stock 1 after ithas been formed through some suitable process such as punching dieforming, or extruding into a substantially channel-shaped member 1having a pair of side walls 3 and 4 and an end wall 5 with respectiveflange members 6 and 7 extending outwardly from one end of each sidewall. Each flange member forms an essentially right angle at the ends ofeach side wall.

In FIG. 3 the flange members 6 and 7 have been bent in a second formingstep to form first sections 8 and 8a and second sections 9 and 9a withthe second sections '3 cl? overlying respective first sections andextending inwardly past respective side walls 3 and 4 to form finmembers 10 and 11.

FIG. 4 is an elevational view of a second piece of blank stock prior toforming steps to produce second half of the anode assembly. The blankpiece of stock as shown in FIG. 4 has previously been subjected to anembossing operation forming corrugations 13 and 14, which extendlongitudinally the length of the piece of stock. It should be obvious toone skilled in the art that the embossing to form corrugations 13 and 14can be done prior to the forming steps in manufacturing the anode andfin assembly or it can be done after the piece of blank has been formedinto the desired shape for the anode structure. FIG. is an elevationalview of the second piece of blank stock after the first formingoperation, which again may be a punching operation die forming, orextruding process to form a second channelshaped member 15 having a pairof side walls 17 and and an end wall 19 with respect to flange members21 and 22 extending outwardly from each end of the side walls 17 and 18and adapted to overlie respective flange members of the firstchannel-shaped member 1.

At this juncture in the operation, the two channel shaped members shownat FIG. 2 and at 15 (FIG. 5) may be secured together by any knownsecuring means such as welding or staking or by striking tongues in oneset of flange members e.g. 6. 7 on channel-shaped member 21 and openingsin the flange members 21, of the second channel-shaped member 15 throughwhich the tongues on the first flange members will pass as shown inPatent 2,843,787. However, an additional operation which will provide animproved anode structure is produced by bending the ends of flangemembers 21 and 22 of the second channel-shaped member 15 to formportions 23 and 24 at essentially 90 angles with respective flangemembers. When the two channel-shaped members are joined together, thesebent portions 23 and 24 may, if desired, be formed to overlap the flangemembers 5 and 6 of the first channel-shaped member 1, as shown in FIG.6, to more firmly secure the two channel-shaped members together, or,the portions 23 and 24, as shown in the top View of the completed anodeassembly in FIG. 7 may extend beyond the flange members 5 and 6.

As has been previously stated, when a beam power tube of the typedescribed above is used in the horizontal deflection system of atelevision receiver, the tube may cause transient or spuriousoscillations or snivets to be generated which will result in vertical.lines on the picture tube of the television receiver. In a beam powertube using the fin assembly produced by the method of manufacturedescribed above and resulting in internal fins 9 and 1; (FIG. 6),spurious oscillations are eliminated or so greatly reduced that nointerfering lines are apparent on a television receiver. It, should beobvious to one skilled in the art that beam power tubes incorporatingthis feature may 3150 be used toreduce high frequency interference inthe outputof radio receivers.

It should be further noted that in the process of manufacture oftheanode the longitudinaledges of the fins and 11 may be serrated tothereby offer substantially reduced secondary-electron-producingsurfaces.

FIG. 7 is a top view of a beam power tube with the tube envelope 30enclosing the anodestructure of the subject invention comprising the twochannel-shaped halves 1 and along with cathode 31, control grid 52,screen grid 33, and beam confining plates 34. disposed so as to confineoppositely directed electron beam 35-35 therebetween.

In FIG. 8 there is showna graph indicating an improvement in the tubecharacteristicsresulting from utilizationof the internal fin assembly ofthe inventionwhich removes the sharpness in the knee of the tubecharacteristics as indicated by the broken lines therein.

An anode structure as shown by FIG. 6 may be pro-.

duced with greater easeof fabrication and reduced cost. The fin assemblyis integral with the anode halves, therefore no additional material inthe form of fin inserts is required. Further, it should be noted that inlining up the anode halves 1 and 15 prior to joining them, there is noneed to line up an additional structure such as a fin insert assembly.

Although a particular embodiment of the subject invention has beendescribed, many modificaitons may be made and it is understood to be theintention of the appended claims to cover all such modifications thatfall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An anode electrode for a discharge device compris- (a) a firstsubstantially channel-shaped member having a pair of side walls and anend wall with a respective flange member extending outwardly from oneend of each side wall and each forming an essentially right angle witheach side wall,

(b) each of the flange members having means defining first and secondsections having an intermediate bight portion, the second sectionsintegral with and overlying the first sections and extending inwardlypast the side walls to form respective fin members,

(0) a second channel-shaped member having a pair of side walls and anend wall, a respective flange member extending outwardly from one end ofeach side wall and overlying respective flange members of the firstchannel-shaped member, said flange members of said second channel-shapedmember further having portions bent toward and disposed adjacent to thebight portions of the respective flange members of said firstchannelshaped member, and

((1) means securing said first and second channel members together.

2. An electron discharge. device, comprising an anode electrode, saidanode electrode comprising,

(a) a first subtantially channel-shaped member having a pair of sidewalls and an end wall, a respective flange member extending outwardlyfrom the free end of each side wall,

(b) each of said flange members having respective first and secondsections having an intermediate bight portion, said first and secondsections being integral with said channel-shaped member and incontinuous heat conducting relation therewith, the second sectionsoverlying the first sections and extending inwardly beyondthe side wallsto form respective fin members,

(c)- a second channel-shaped member having a pair of side walls and anend wall, said side walls having respective flange members extendingoutwardly therefrom and overlying respective flange members of the firstchannel-shaped member,

(0!) the free ends of the flange members of the second channel-shapedmember projecting beyond the free ends of andpositioned adjacent to thebight portions of the flange members of the first channel-shaped member,and

(e) means securing said first and second channel-shaped memberstogether.

3. The method for forming an anode electrode for discharge devicecomprising,

(a) forming a sheet of material into a first substantial channel-shapedmember having a pair of side walls and an end wall with a respectiveflange member extending outwardly from one end of each side Wall andeach forming an essentially right angle with the ends of each side wall,

([2) bending each of the flange members to form respective first andsecond sections having an intermediate bight portion with the secondsections overlying the first sections and extending inwardly to pass theside walls to form respective fin members,

(c) forming a second sheet of material into a second channel-shapedmember having a pair of side Walls and an end Wall with a respectiveflange member extending outwardly from one end of each side Wall andoverlying respective flange members of the first channel-shaped member,said flange members of said second channel-shaped member further havingbent portions,

(d) embossing each flange member of said second channel-shaped member toform corrugations extending longitudinally the length of each flangemember,

(e) positioning said second channel-shaped member so that the bentportions of the flange members of said second channel-shaped member aredirected toward and disposed adjacent to the bight portions of therespective flange member of said first channel-shaped member, and

(f) securing said first and second channel-shaped members together.

4. The method of forming an anode electrode for a discharge devicecomprising,

(a) forming a sheet of material into a first substantiallychannel-shaped member having a pair of side walls and an end wall with arespective flange member extending outwardly from one end of each sidewall and each flange member forming an essentially right angle with theends of each side wall,

(b) bending each of the flange members to form respective first andsecond sections having an intermediate bight portion with the secondsections overlying the first sections and extending inwardly past theside walls to form respective fin members,

(c) forming a second sheet of material into a second channel-shapedmember having a pair of side Walls and an end wall with a respectiveflange member extending outwardly from one end of each side Wall andadapted to overlie respective flange members of the first channel-shapedmember,

(d) embossing each flange member of said second channel-shaped member toform a corrugation extending longitudinally the length of each flangemember,

(e) bending the ends of the flange members of the second channel-shapedmember to overlap the flange members of the first channel-shaped member,and

(f) securing the first and second channel-shaped members together.

5. An anode electrode for a discharge device compris- (a) a firstsubstantially channel-shaped member having a pair of side walls and anend wall with a respective flange member extending outwardly from oneend of each side Wall and each forming an essentially right angle withthe ends of each side wall,

(b) each of said flange members comprising integral first and secondsections having an intermediate bight portion with the second sectionsoverlying the first sections and extending inwardly past the side wallsto form respective fin members,

(0) a second substantially channel-shaped member having a pair of sidewalls and an end wall with a respective flange member extendingoutwardly from one end of each side wall forming an essentially rightangle with the ends of each side wall and overlying respective flangemembers of the first channel-shaped member, said flange members of saidsecond channelshaped member further having portions 'bent toward anddisposed adjacent to the bight portions of the respective flange membersof said first channel-shaped member, and

(d) means to secure said first and second channelshaped members togetherto thereby form the anode assembly.

6. An anode electrode for a discharge device compris- (a) a firstsubstantially channel-shaped member having a pair of side walls and anend wall with a respective flange member extending outwardly from oneend of each side wall and each forming an essentially right angle withthe ends of each side wall,

(b) each of said flange members comprising integral first and secondsections having an intermediate bight portion, with the second sectionsoverlying the first sections and extending inwardly past the side wallsto form respective fin members,

(0) a second substantially channel-shaped member having a pair of sidewalls and an end wall with respec tive flange members of said secondchannel-shaped member overlying the adjacent second section of the firstchannel-shaped member,

(d) tab members projecting from the free ends of the respective flangemembers of the second channelshaped member and overlapping the bightportions of the respective flange members of the first channelshapedmember securing said first and said second channel-shaped memberstogether, and

(e) additional means to secure said first and second channel-shapedmembers together to thereby form the anode assembly.

References Cited in the file of this patent UNITED STATES PATENTS

1. AN ANODE ELECTRODE FOR A DISCHARGE DEVICE COMPRISING, (A) A FIRSTSUBSTANTIALLY CHANNEL-SHAPED MEMBER HAVING A PAIR OF SIDE WALLS AND ANEND WALL WITH A RESPECTIVE FLANGE MEMBER EXTENDING OUTWARDLY FROM ONEEND OF EACH SIDE WALL AND EACH FORMING AN ESSENTIALLY RIGHT ANGLE WITHEACH SIDE WALL, (B) EACH OF THE FLANGE MEMBERS HAVING MEANS DEFININGFIRST AND SECOND SECTIONS HAVING AN INTERMEDIATE BIGHT PORTION, THESECOND SECTIONS INTEGRAL WITH AND OVERLYING THE FIRST SECTIONS ANDEXTENDING INWARDLY PAST THE SIDE WALLS TO FORM RESPECTIVE FIN MEMBERS,(C) A SECOND CHANNEL-SHAPED MEMBER HAVING A PAIR OF SIDE WALLS AND ANEND WALL, A RESPECTIVE FLANGE MEMBER EXTENDING OUTWARDLY FROM ONE END OFEACH SIDE WALL AND OVERLYING RESPECTIVE FLANGE MEMBERS OF THE FIRSTCHANNEL-SHAPED MEMBER, SAID FLANGE MEMBERS OF SAID SECOND CHANNEL-SHAPEDMEMBER FURTHER HAVING PORTIONS BENT TOWARD AND DISPOSED ADJACENT TO THEBIGHT PORTIONS OF THE RESPECTIVE FLANGE MEMBERS OF SAID FIRSTCHANNEL-SHAPED MEMBER, AND (D) MEANS SECURING SAID FIRST AND SECONDCHANNEL MEMBERS TOGETHER.